Abstract

We report for the first time successful growth of magnetic thin films containing the Gd5(SixGe1−x)4 phase, which is expected to show giant magnetocaloric properties. The film was deposited by Pulsed Laser Deposition(PLD) on a (001) silicon wafer at 200 °C from a polycrystalline Gd5Si2.09Ge1.91 target prepared by arc melting. PLD was achieved using a femto second laser with a repetition rate of 1 kHz, and a pulse energy of up to 3.5 mJ. The average film thickness was measured to be 400 nm using a Scanning Electron Microscopy and the composition of the film was analyzed using Energy Dispersive Spectroscopy and found to be close to the target composition. X-Ray Diffraction analysis confirmed the presence of Gd5Si2Ge2 monoclinic structure. Magnetic moment vs. magnetic field measurement confirmed that the film was ferromagnetic at a temperature of 200 K. The transition temperature of the film was determined from a plot of magnetic moment vs. temperature. The transition temperature was between 280 and 300 K which is close to the transition temperature of the bulk material.

Received 01 November 2012Accepted 24 January 2013Published online 09 April 2013

Acknowledgments:

This work at the Ames Laboratory was supported by the DOE-Basic Energy Sciences under Contract No. DE-AC02-07CH11358 and Barbara and James Palmer Endowment at the Department of Electrical and Computer Engineering of Iowa State University. The authors acknowledge the contributions of A. H. Shaw and K. W. Dennis Ames Laboratory, US DOE for helping with the PLD and SQUID measurements, respectively.

Key Topics

[Magnets or magnetic bodies characterised by the
magnetic materials therefor; Selection of materials for their magnetic
properties, Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties]